The Biostatistics Core will assist the Center in its efforts to quantify the role of genetic and pharmacologic influences of seroteronergic modulation on the development of brain structure and functioning, and of behaviour. The Biostatistics Core will focus on providing resources for consultation and periforming statistical analysis for all projects. Specifically, we will assist in meeting Center goals by: 1) assisting in the statistical design and power analysis of all center projects; 2) performing statistical analyses on data from a large birthcohort study to determine effects of maternal SRI exposure on development and neuropsychiatric outcomes in offspring; 3) performing statistical analyses on brain imaging data as well as data on clinical endophenotypes of depression, to quantify Shtllpr genotype and other interacting genotype-specific changes in brain structure/function, as well as association of these genes with clinical endophenotypes and neurophysiologic measures in a high risk 3-generation cohort; 4) performing statistical analysis to determine the effect of SSRI exposure and genetic factors on infant brain structure and neurophysiology and eariy life temperament; and 5) assisting in analyzing data generated from animal models to determine serotoninmediated genetic and pharmacologic influences on developing brain structure across species. In addition, investigators in the Biostatistics Core will work closely with those in the genetics and imaging cores to develop novel and sophisticated statistical methods to integrate phenotypic, genotypic, neurophysiologic, and imaging data. These activities will be accomplished by regular individual and group meetings with project and core directors, to review data and suggest statistical approaches. Students from T32 training grants, both graduate students and fellows, will also be involved in this work.